Everybodys', and often. Jewish goldsmiths were the first bank-vault-providers, and they soon had a very unsavoury reputation for stealing and ponzi-scamming ("fractional reserve"). So they started offering a return instead of charging storage fees. Which worked well and brought in lots of whales. Until a banker decided to exit-scam, or until some whale got nervous and asked to see his gold. Then "Government! Do something!".